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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-09-07 18:22:28 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-01-03 04:33:35 +0000 |
| commit | b5c70f452589114e6a551803bf312eed1b57f964 (patch) | |
| tree | 1e57c8fa12e52f8dd9c51a3957a274e3fa82a7a3 /arch/arm/lib | |
| parent | 960c9d696b30cfed659cd56d4c7f1bfac7d9c424 (diff) | |
| download | lwn-b5c70f452589114e6a551803bf312eed1b57f964.tar.gz lwn-b5c70f452589114e6a551803bf312eed1b57f964.zip | |
ARM: 7527/1: uaccess: explicitly check __user pointer when !CPU_USE_DOMAINS
commit 8404663f81d212918ff85f493649a7991209fa04 upstream.
The {get,put}_user macros don't perform range checking on the provided
__user address when !CPU_HAS_DOMAINS.
This patch reworks the out-of-line assembly accessors to check the user
address against a specified limit, returning -EFAULT if is is out of
range.
[will: changed get_user register allocation to match put_user]
[rmk: fixed building on older ARM architectures]
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[bwh: Backported to 3.2: TUSER() was called T()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/arm/lib')
| -rw-r--r-- | arch/arm/lib/getuser.S | 23 | ||||
| -rw-r--r-- | arch/arm/lib/putuser.S | 6 |
2 files changed, 21 insertions, 8 deletions
diff --git a/arch/arm/lib/getuser.S b/arch/arm/lib/getuser.S index 1b049cd7a49a..4306fbf8cf86 100644 --- a/arch/arm/lib/getuser.S +++ b/arch/arm/lib/getuser.S @@ -16,8 +16,9 @@ * __get_user_X * * Inputs: r0 contains the address + * r1 contains the address limit, which must be preserved * Outputs: r0 is the error code - * r2, r3 contains the zero-extended value + * r2 contains the zero-extended value * lr corrupted * * No other registers must be altered. (see <asm/uaccess.h> @@ -27,33 +28,39 @@ * Note also that it is intended that __get_user_bad is not global. */ #include <linux/linkage.h> +#include <asm/assembler.h> #include <asm/errno.h> #include <asm/domain.h> ENTRY(__get_user_1) + check_uaccess r0, 1, r1, r2, __get_user_bad 1: T(ldrb) r2, [r0] mov r0, #0 mov pc, lr ENDPROC(__get_user_1) ENTRY(__get_user_2) -#ifdef CONFIG_THUMB2_KERNEL -2: T(ldrb) r2, [r0] -3: T(ldrb) r3, [r0, #1] + check_uaccess r0, 2, r1, r2, __get_user_bad +#ifdef CONFIG_CPU_USE_DOMAINS +rb .req ip +2: ldrbt r2, [r0], #1 +3: ldrbt rb, [r0], #0 #else -2: T(ldrb) r2, [r0], #1 -3: T(ldrb) r3, [r0] +rb .req r0 +2: ldrb r2, [r0] +3: ldrb rb, [r0, #1] #endif #ifndef __ARMEB__ - orr r2, r2, r3, lsl #8 + orr r2, r2, rb, lsl #8 #else - orr r2, r3, r2, lsl #8 + orr r2, rb, r2, lsl #8 #endif mov r0, #0 mov pc, lr ENDPROC(__get_user_2) ENTRY(__get_user_4) + check_uaccess r0, 4, r1, r2, __get_user_bad 4: T(ldr) r2, [r0] mov r0, #0 mov pc, lr diff --git a/arch/arm/lib/putuser.S b/arch/arm/lib/putuser.S index c023fc11e86c..9a897fab4d97 100644 --- a/arch/arm/lib/putuser.S +++ b/arch/arm/lib/putuser.S @@ -16,6 +16,7 @@ * __put_user_X * * Inputs: r0 contains the address + * r1 contains the address limit, which must be preserved * r2, r3 contains the value * Outputs: r0 is the error code * lr corrupted @@ -27,16 +28,19 @@ * Note also that it is intended that __put_user_bad is not global. */ #include <linux/linkage.h> +#include <asm/assembler.h> #include <asm/errno.h> #include <asm/domain.h> ENTRY(__put_user_1) + check_uaccess r0, 1, r1, ip, __put_user_bad 1: T(strb) r2, [r0] mov r0, #0 mov pc, lr ENDPROC(__put_user_1) ENTRY(__put_user_2) + check_uaccess r0, 2, r1, ip, __put_user_bad mov ip, r2, lsr #8 #ifdef CONFIG_THUMB2_KERNEL #ifndef __ARMEB__ @@ -60,12 +64,14 @@ ENTRY(__put_user_2) ENDPROC(__put_user_2) ENTRY(__put_user_4) + check_uaccess r0, 4, r1, ip, __put_user_bad 4: T(str) r2, [r0] mov r0, #0 mov pc, lr ENDPROC(__put_user_4) ENTRY(__put_user_8) + check_uaccess r0, 8, r1, ip, __put_user_bad #ifdef CONFIG_THUMB2_KERNEL 5: T(str) r2, [r0] 6: T(str) r3, [r0, #4] |